#include<iostream>
#include<vector>
#include<string>
using namespace std;

struct TreeNode {
     int val;
     TreeNode *left;
     TreeNode *right;
     TreeNode() : val(0), left(nullptr), right(nullptr) {}
     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 };

void recoverTree(TreeNode* root) {
    TreeNode* cur = root->left;
}
int main()
{
    TreeNode* root = new TreeNode(3);
    TreeNode* cur = root;
    cur->left = new TreeNode(1);
    cur->right = new TreeNode(4);
    cur = cur->right;
    cur->left = new TreeNode(2);
    recoverTree(root);
    return 0;
}